Yes, Sailor, the bubbly urine is the caused by air passing from your bowel into your bladder. My local GI said he could see that on a CT scan I had, along with an abscess. When it and the fistula didn't heal on Pred and Aza, he referred me to hospital on the mainland for surgery.
When I finally got there, they did a colonoscopy and another CT scan and told me that the abscess had shrunk, but that my TI was still very inflamed. They recommended trying the Infliximab.
After the brief respite, I emailed my IBD nurse when I started getting symptoms again and he spoke to my GI who called me over to the mainland for a couple of days for tests. An MRI showed that the fistula had opened again and the colorectal surgeon came to see me the day after I got the result. He said he could do the surgery the next day.
I was a bit taken aback and wanted time to think about it, but he said the constant UTIs were putting my kidneys in danger and why didn't we just sort it while I was there, so I agreed. I'd had chronic back pain since first becoming ill and that went after the surgery.